Primary Hyperaldosteronism

Question 1

What is primary hyperaldosteronism?

Answer 1

Autonomous aldosterone overproduction from the adrenal gland with subsequent suppression of plasma renin activity

Question 2

Give the 2 main causes of primary hyperaldosteronism?

Answer 2

Idiopathic bilateral adrenal hyperplasia (60%)

Adrenal adenoma: Conn’s syndrome (40%)

Question 3

What rare causes are there for primary hyperaldosteronism?

Answer 3

Familial hyperaldosteronism

Aldosterone producing adrenal carcinoma

Question 4

Describe the pathophysiology of primary hyperaldosteronism

Answer 4

Excess aldosterone causes increased Na+ + water retention
Leads to increased blood volume + HTN
Also causes increased renal K+ loss leading to hypokalaemia
Renin is suppressed due to NaCl retention

Question 5

Describe the epidemiology of primary hyperaldosteronism

Answer 5

5-10% of hypertensive patients
Conn’s syndrome F > M
Bilateral adrenal hyperplasia M>F

Question 6

List 7 symptoms hypokalaemia

Answer 6

Fatigue 
Muscle weakness
Headaches
Constipation 
Palpitations  
Polyuria + polydipsia (due to nephrogenic DI) 
Paraesthesia (metabolic alkalosis)

Question 7

List 4 signs of primary hyperaldosteronism

Answer 7

HTN (drug resistant) 
Complications of HTN e.g.
Headaches
Facial flushing
Hypertensive retinopathy

Question 8

What screening tests can be used for primary hyperaldosteronism?

Answer 8

Low Serum K+  
Normal/ mild hypernatraemia as Na+ reabsorption is matched by water reabsorption  
High Urine K+ 
High Plasma Aldosterone Concentration 
High aldosterone: renin activity ratio

Question 9

What confirmatory tests can be used for primary hyperaldosteronism?

Answer 9

Salt Loading
Failure of aldosterone suppression following salt load
CT/MRI: to detect tumour or hyperplasia

Question 10

Why perform a bilateral adrenal vein catheterisation?

Answer 10

Measures adrenal vein aldosterone levels
Conn’s syndrome: discrepancy between adrenal levels
Bilateral adrenal hyperplasia: no difference between sides

Question 11

How does Radio-labelled cholesterol scanning differentiate between causes of primary hyperaldosteronism?

Answer 11

Unilateral uptake in adrenal adenomas

Bilateral uptake in bilateral adrenal hyperplasia

Question 12

Describe the management of bilateral adrenal hyperplasia

Answer 12

Spironolactone or Eplerenone
Amiloride (K+ sparing diuretic)
Monitor serum K+, creatinine + BP
ACEi + CCBs may also be added

Question 13

Describe the management of Conn’s syndrome

Answer 13

Adrenalectomy

Question 14

Describe the management of an adrenal carcinoma

Answer 14

Surgery

Post-operative mitotane (antineoplastic)

Question 15

What complications may arise due to primary hyperaldosteronism?

Answer 15

Complications of HTN

Question 16

What is the prognosis in primary hyperaldosteronism?

Answer 16

Surgery may cure HTN

Or may make HTN easier to treat with anti-hypertensive medication

Question 17

What are the main consequences of high aldosterone?

Answer 17

Increased Na + water retention, increases blood volume + BP = HTN + HYPERNATRAEMIA
Increased K+ excretion = HYPOKALAEMIA
Increased H+ excretion = ALKALOSIS

Question 18

How does primary hyperaldosteronism usually present?

Answer 18

Often asymptomatic

Often incidental finding